nanog mailing list archives
Re: looping traceroutes
From: "Patrick W. Gilmore" <patrick () ianai net>
Date: Wed, 19 Sep 2001 00:40:55 -0400
At 09:31 PM 9/18/2001 -0700, Ratul Mahajan wrote: [SNIP] >28 193.251.133.117 (193.251.133.117) 586.776 ms 584.171 ms 586.944 ms >29 193.251.133.117 (193.251.133.117) 608.677 ms 610.789 ms 618.232 ms >30 193.251.133.117 (193.251.133.117) 641.141 ms 643.149 ms 639.050 msThis sometimes happens when there is a filter on that router. All packets going through get an ICMP administratively denied sent back, and the traceroute host interprets that as an ICMP TTL expired or perhaps does not even notice what type of ICMP it is, just looks at the source IP address.
>27 208.63.128.3 (208.63.128.3) 111.475 ms 69.670 ms 69.267 ms >28 208.63.128.1 (208.63.128.1) 68.883 ms 67.147 ms 72.106 ms >29 208.63.128.3 (208.63.128.3) 69.842 ms 67.889 ms 66.944 ms >30 208.63.128.1 (208.63.128.1) 70.986 ms 73.124 ms 68.452 msThis looks exactly like a routing loop to me. Why do you think it is not a routing loop?
-- TTFN, patrick
Current thread:
- looping traceroutes Ratul Mahajan (Sep 18)
- Re: looping traceroutes Stephen J. Wilcox (Sep 19)
- <Possible follow-ups>
- Re: looping traceroutes Patrick W. Gilmore (Sep 18)
- Re: looping traceroutes Ratul Mahajan (Sep 19)
- Re: looping traceroutes Stephen Stuart (Sep 19)
- Re: looping traceroutes Leo Bicknell (Sep 19)
- Re: looping traceroutes Nick Feamster (Sep 19)
- Re: looping traceroutes Ratul Mahajan (Sep 19)
- Re: looping traceroutes Marshall Eubanks (Sep 19)
- RE: looping traceroutes Jeb R. Linton (Sep 19)
- RE: looping traceroutes Hire, Ejay (Sep 19)